1. Field of the Invention
Aspects of the present invention are directed to processing of a video signal, and more particularly to a system and method for signal processing that determines motion in a digital video signal.
2. Background of the Invention
Video signals include a series of images, or frames, played in succession, and can include a series of frames each divided into two fields. One field contains odd lines of pixels in a frame, and the other field contains even lines of pixels in a frame. Dividing each frame into a set of odd fields and a set of even fields reduces the amount of bandwidth necessary to transmit a video signal. Historically, displaying a video signal with alternating odd and even fields reduced or eliminated levels of visible flicker in the displayed video signal.
Some video signals are not well suited for modern computer monitor or televisions, such as those with plasma, liquid crystal, or other displays that support high definition formats. For optimal performance these devices and others generally use a video signal where a frame includes all fields, odd and even, of a video signal. In certain video signals the odd and even fields are successively scanned, and as a result an object that is in motion may be in one position during scanning of one field, and may be in a different position during subsequent scanning of another field. Motion of objects that takes place in the time period between the odd and even field scans of a video signal results in visually perceptible and undesirable artifacts. These artifacts can be encoded into the video signal. Motion that is present between the odd an even fields of a frame manifests itself as an unwanted artifact that degrades the image of the video signal. These schemes are imperfect, as various distortions appear in a display of the video signal, reducing its quality on both standard and high definition displays.